From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: mmotm 2010-02-10 - lockdep whinge in ACPI code Date: Wed, 10 Feb 2010 21:26:55 -0800 Message-ID: <20100210212655.7784dc5b.akpm@linux-foundation.org> References: <201002110043.o1B0hKxW008835@imap1.linux-foundation.org> <5114.1265865104@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:50004 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783Ab0BKF2C (ORCPT ); Thu, 11 Feb 2010 00:28:02 -0500 In-Reply-To: <5114.1265865104@localhost> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Valdis.Kletnieks@vt.edu Cc: Len Brown , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Greg KH , Kay Sievers , Thomas Gleixner On Thu, 11 Feb 2010 00:11:44 -0500 Valdis.Kletnieks@vt.edu wrote: > On Wed, 10 Feb 2010 16:17:41 PST, akpm@linux-foundation.org said: > > The mm-of-the-moment snapshot 2010-02-10-16-17 has been uploaded to > > > > http://userweb.kernel.org/~akpm/mmotm/ > > Seen at boot: > > [ 0.207242] ACPI: (supports S0 S5) > [ 0.207257] ACPI: Using IOAPIC for interrupt routing > [ 0.335315] > [ 0.335316] ============================================= > [ 0.335483] [ INFO: possible recursive locking detected ] > [ 0.335572] 2.6.33-rc7-mmotm0210 #1 > [ 0.335658] --------------------------------------------- > [ 0.335746] swapper/1 is trying to acquire lock: > [ 0.335834] (&dev->mutex){+.+...}, at: [] __driver_attach+0x47/0x80 > [ 0.335999] > [ 0.335999] but task is already holding lock: > [ 0.335999] (&dev->mutex){+.+...}, at: [] __driver_attach+0x39/0x80 > [ 0.335999] > [ 0.335999] other info that might help us debug this: > [ 0.335999] 1 lock held by swapper/1: > [ 0.335999] #0: (&dev->mutex){+.+...}, at: [] __driver_attach+0x39/0x80 > [ 0.335999] > [ 0.335999] stack backtrace: > [ 0.335999] Pid: 1, comm: swapper Not tainted 2.6.33-rc7-mmotm0210 #1 > [ 0.335999] Call Trace: > [ 0.335999] [] __lock_acquire+0xc77/0xcee > [ 0.335999] [] ? mark_lock+0x2d/0x22c > [ 0.335999] [] ? __driver_attach+0x47/0x80 > [ 0.335999] [] lock_acquire+0xcb/0xe8 > [ 0.335999] [] ? __driver_attach+0x47/0x80 > [ 0.335999] [] ? mark_held_locks+0x52/0x70 > [ 0.335999] [] __mutex_lock_common+0x5c/0x5aa > [ 0.335999] [] ? __driver_attach+0x47/0x80 > [ 0.335999] [] ? klist_next+0x24/0xd7 > [ 0.335999] [] ? __driver_attach+0x47/0x80 > [ 0.335999] [] ? __driver_attach+0x0/0x80 > [ 0.335999] [] mutex_lock_nested+0x34/0x39 > [ 0.335999] [] __driver_attach+0x47/0x80 > [ 0.335999] [] ? __driver_attach+0x0/0x80 > [ 0.335999] [] ? __driver_attach+0x0/0x80 > [ 0.335999] [] bus_for_each_dev+0x54/0x89 > [ 0.335999] [] driver_attach+0x19/0x1b > [ 0.335999] [] bus_add_driver+0xb4/0x203 > [ 0.335999] [] driver_register+0xb8/0x129 > [ 0.335999] [] acpi_bus_register_driver+0x3e/0x40 > [ 0.335999] [] acpi_ec_init+0x37/0x55 > [ 0.335999] [] acpi_init+0x115/0x12a > [ 0.335999] [] ? acpi_init+0x0/0x12a > [ 0.335999] [] do_one_initcall+0x59/0x14e > [ 0.335999] [] kernel_init+0x14d/0x1a3 > [ 0.335999] [] kernel_thread_helper+0x4/0x10 > [ 0.335999] [] ? restore_args+0x0/0x30 > [ 0.335999] [] ? kernel_init+0x0/0x1a3 > [ 0.335999] [] ? kernel_thread_helper+0x0/0x10 > [ 0.340036] ACPI: EC: GPE = 0x11, I/O: command/status = 0x934, data = 0x930 > driver_attach() got converted from sem to mutex in linux-next. So this is probably an old bug which just got exposed. Or maybe not. Thomas, has that patch been in some other tree (rt?) for a while? If so, was this bug observed in that tree? If not, it might be new.